[1] Univ British Columbia, Combined Neurosurg & Orthoped Spine Program, Dept Orthoped Surg, 818 West 10th Ave, Vancouver, BC V5Z 1M9, Canada
[2] Univ Calgary, Combined Neurosurg & Orthoped Spine Program, 1403-29th St NW, Calgary, AB T2N 2T9, Canada
[3] Univ Laval, CHU Quebec, Ctr Rech, 1401 18e Rue, Quebec City, PQ G1J 1Z4, Canada
[4] Univ Toronto, Div Orthopaed & Neurosurg, 149 Coll St room 508-A, Toronto, ON M5T 1P5, Canada
[5] Univ Toronto, Dept Surg, 149 Coll St room 508-A, Toronto, ON M5T 1P5, Canada
[6] Western Univ, London Hlth Sci Ctr, Dept Orthoped Surg, 339 Windermere Rd, London, ON N6A 5A5, Canada
[7] McGill Univ, Hlth Ctr, Dept Orthoped Surg, 1650 Cedar Ave,B5 159-6, Montreal, PQ H3G 1A4, Canada
[8] Univ Alberta Hosp, Walter C Mackenzie Hlth Sci Ctr, Div Neurosurg Dept Surg, 8440-112 St, Edmonton, AB T6G 2B7, Canada
[9] Horizon Hlth Network, Div Neurosurg, Canada East Spine Ctr, Zone 2,400 Univ Ave, St John, NB E2L 4L2, Canada
[10] Univ Hlth Network, Schroeder Arthrit Inst, Krembil Res Inst, 522 Univ Ave Su 1001, Toronto, ON M5G 2C4, Canada
[11] Univ Toronto, Dept Surg, Orthopaed, 149 Coll St room 508-A, Toronto, ON M5T 1P5, Canada
[12] Ottawa Hosp, Dept Orthoped Surg, 1053 Carling Ave, Ottawa, ON K1Y 4E9, Canada
[13] Dalhousie Univ, Div Neurosurg, 3806-1796 Summer St, Halifax, NS B3H 3A7, Canada
[14] Canadian Spine Outcomes & Res Network, Box 1053, Markdale, ON N0C 1H0, Canada